A novel synthesis of 2,4,6-trithiaheptane and its conversion into 2,6-bis(methylthio)thiane. Spectral properties of some thiaalkanes

1981 ◽  
Vol 59 (2) ◽  
pp. 326-332 ◽  
Author(s):  
J. Stuart Grossert ◽  
Donald L. Hooper ◽  
William M. Neaves
Keyword(s):  
Long Range ◽  
Spectral Properties ◽  
Mass Spectra ◽  
Fragmentation Pathway ◽  
Coupling Constants ◽  
Spectral Studies ◽  
Proton Coupling ◽  
Novel Synthesis ◽  
C Nmr

2,4,6-Trithiaheptane (1a) has been prepared by lithium tetrahydridoaluminate reduction of the methiodide of 1,3,5-trithiane (2). Treatment of 1a with strong bases permitted formation of 3-alkylated derivatives (3) which could in turn be converted into diastereomeric mixtures of 3,5-dialkyl derivatives (4). A two-step alkylation of 1a with 1-bromo-3-chloropropane led to the formation of 2,6-bis(methylthio)thiane (5). Proton and 13C nmr spectral studies on these compounds, including the measurement of long-range carbon–proton coupling constants, are described; their mass spectra showed elimination of methanethiol as a characteristic major fragmentation pathway.

21,22-Disubstituted 18α,19βH-Ursane Derivatives with Oxabicyclooctane System in Ring E

1993 ◽  
Vol 58 (1) ◽  
pp. 173-190 ◽  
Author(s):  
Eva Klinotová ◽  
Jiří Klinot ◽  
Václav Křeček ◽  
Miloš Buděšínský ◽  
Bohumil Máca
Keyword(s):  
Spectral Data ◽  
Spin Systems ◽  
Coupling Constants ◽  
Complete Analysis ◽  
Nmr Spectrum ◽  
Proton Proton ◽  
H Nmr ◽  
Proton Coupling ◽  
C Nmr

Reaction of 3β-acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) and 20β,28-epoxy-21,22-dioxo-19α,19βH-ursan-3β-yl acetate (IIIb) with diazomethane afforded derivatives XII-XIV with spiroepoxide group in position 21 or 22, which were further converted into hydroxy derivatives XV and XVII. Ethylene ketals VIII-X were also prepared. In connection with the determination of position and configuration of the functional groups at C(21) and C(22), the 1H and 13C NMR spectral data of the prepared compounds are discussed. Complete analysis of two four-spin systems in the 1H NMR spectrum of bisethylenedioxy derivative Xb led to the proton-proton coupling constants from which the structure with two 1,4-dioxane rings condensed with ring E, and their conformation, was derived.

Concerning a relationship between long-range ring proton – methyl proton coupling constants and mobile bond order

1968 ◽  
Vol 46 (4) ◽  
pp. 654-656 ◽  
Author(s):  
D. J. Blears ◽  
S. S. Danyluk ◽  
T. Schaefer
Keyword(s):  
Linear Relationship ◽  
Long Range ◽  
Bond Order ◽  
Coupling Constants ◽  
Methyl Proton ◽  
Methyl Group ◽  
Potential Barriers ◽  
Proton Coupling ◽  
Induced Changes ◽  
Excitation Parameters

Long-range proton – methyl proton coupling constants in propene, mesitylene, 9-methylphenanthrene, and acenaphthene appear to be linearly related to the square of the mobile bond order between the carbon atoms bonded to the methyl group and the proton. However, substituent-induced changes in the charge on and hybridization state of the carbon atoms, in excitation parameters and in potential barriers to rotation of the methyl group, may also affect the coupling. Such changes must be considered in the application of a possible linear relationship.

An Investigation of Long-range Proton–Proton Coupling Constants in Phenylacetylene Derivatives

1972 ◽  
Vol 50 (13) ◽  
pp. 2035-2040 ◽  
Author(s):  
C. J. MacDonald ◽  
G. K. Hamer ◽  
I. R. Peat ◽  
W. F. Reynolds
Keyword(s):  
Hyperfine Interaction ◽  
Long Range ◽  
Excellent Agreement ◽  
Quantitative Estimation ◽  
Theoretical Calculations ◽  
Experimental Results ◽  
Coupling Constants ◽  
Proton Proton ◽  
Proton Coupling

Signs and magnitudes of long-range coupling constants in three phenylacetylene derivatives have been determined. Values of the coupling constants are discussed in terms of the McConnell formulation and compared with results of MO–INDO–FPT calculations. Coupling constants are dominated by π contributions. Estimated values of hyperfine interaction constants for acetylene and methylacetylene groups are respectively QCC≡CH = −12 and QCC≡CCH = +12 G. The theoretical calculations are in excellent agreement with experimental results. Both approaches allow quantitative estimation of nine bond couplings in 4-vinylphenylacetylene.

Neue 1-Aza-2 λ5, 4 λ5-diphosphirine (2 λ5, 4 λ5-Diphosphapyridine) / New 1 -Aza-2λ5, 4λ5-diphosphirines (2λ5, 4λ5-Diphosphapyridines)

1991 ◽  
Vol 46 (6) ◽  
pp. 762-766 ◽  
Author(s):  
Ekkehard Fluck ◽  
Manfred Spahn ◽  
Gernot Heckmann
Keyword(s):  
Physical Properties ◽  
Long Range ◽  
Mass Spectra ◽  
Coupling Constants

6-(Furan-2-yl)-2,4-tetrakis(dimethylamino)-1-aza-2λ5, 4λ5-diphosphirine (2) and 6-(N-pyrrolidinyl)-2,4-tetrakis(dimethylamino)-1-aza-2λ5, 45-diphosphirine (3) were prepared by reacting 1,1,3,3-tetrakis(dimethylamino)-1 λ5,3 λ5-diphosphete with 2-cyanofuran, and N-cyanopyrrolidine, respectively. 2 and 3 are characterized by their physical properties, NMR, IR, and mass spectra. In 2 two 6J(PH) long range coupling constants could be identified.

Long range carbon-proton coupling constants in pyridine

1974 ◽  
Vol 6 (3) ◽  
pp. 181-183 ◽  
Author(s):  
Goh Miyajima ◽  
Kensuke Takahashi ◽  
Hiroshi Sugiyama
Keyword(s):  
Long Range ◽  
Coupling Constants ◽  
Proton Coupling
Sign in / Sign up

Export Citation Format

Share Document